Miniature camera applying stepping ultrasonic motor and control method for miniature camera

Abstract

The invention discloses a miniature camera applying a stepping ultrasonic motor and a control method for the miniature camera. The miniature camera applying the stepping ultrasonic motor comprises a motor base, a stator, a rotor, a lens mount and a pre-pressing device, wherein the stator, the rotor and the lens mount are arranged on the motor base in sequence, and the pre-pressing device is used for applying pre-pressure to the lens mount; the stator comprises an elastomer and a piezoelectric ceramic piece, wherein the piezoelectric ceramic piece is arranged on the lower surface of the elastomer and is used for exciting standing-wave vibration; at least two electrodes are arranged on the lower surface of the piezoelectric ceramic piece; at least one contact tooth is arranged on the rotor,and the rotor makes contact with the upper surface of the elastomer through the contact teeth. According to the miniature camera and the control method thereof, the electrodes are controlled to be electrified in different ways, the principle that nodes after standing wave superposition are located between two nodes before standing wave superposition is adopted, and therefore the automatic focusingprecision of the miniature camera applying the stepping ultrasonic motor is improved.

Description

technical field [0001] The invention relates to the field of ultrasonic motors, in particular to a miniature camera using a stepping ultrasonic motor. Background technique [0002] In recent years, scholars at home and abroad have attempted to realize stepping ultrasonic motors by combining the design of special mechanical mechanisms with excitation methods. Theoretically, the single-pulse displacement response of an ultrasonic motor is at the μm or even nm level. In the prior art, the common ultrasonic motor uses a traveling wave motor, which is not accurate enough to fully utilize the advantages of the high step accuracy of the ultrasonic motor, so it cannot be popularized. Applied to miniature application scenarios such as miniature cameras, the automatic focusing of miniature cameras cannot be well realized. [0003] Therefore, the prior art still needs to be improved and developed. Contents of the invention [0004] The technical problem to be solved by the present ...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a micro-camera using a stepping ultrasonic motor and its control method in view of the above-mentioned defects of the prior art, aiming to solve the problem that the stepping ultrasonic motor in the prior art has low stepping precision and cannot Applied to the problem of automatic focusing of miniature cameras

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